Random Noise turing test

Generates random black noise, then text, then random white noise.

Methods
Public Instance methods
generate(img, word, bg = nil)

contract method - generate the challenge

    # File lib/turing/image_plugins/random_noise.rb, line 15
15:         def generate(img, word, bg = nil) # {{{
16:                 fg = GD2::Color[255, 255, 255]
17:                 bg = GD2::Color[0, 0, 0]
18:                 
19:                 0.upto(img.width * img.height * 0.4) do |i|
20:                         img[rand(img.width), rand(img.height)] = bg
21:                 end
22: 
23:                 write_string(img, 'georgiai.ttf', bg, word, 48)
24:                 
25:                 quant = word.size > 7 ? 0.1 : 0.2
26:                 0.upto(img.width * img.height * quant) do |i|
27:                         img[rand(img.width), rand(img.height)] = fg
28:                 end
29:         end